Continuity mistake: When Keith Palmer and Carl Webb meet they stop walking around to talk. When we see Carl's face, the sun is coming from behind him, the light shimmers through his hair and the light reflects on Keith's face. Than it cuts to a view from behind Carl, and there is suddenly no light, both stand in the shadow. (00:34:00)
Continuity mistake: Elizabeth walks away from the security brief and puts her arm on the wall. When David approaches her, her arm is still on the wall. When the camera changes to the front angle, her arm is not on the wall any more. This is an instant cut. (00:06:30)
Answer: According to Jack in season 5, Nina was "deep cover" before the pair ever met, so it's safe to assume she was recruited before she joined CTU. As for what her primary mission was, who knows? Perhaps it was to gather sensitive intel and pass it on to her superiors. Given that she worked for an intelligence agency, it's not a stretch. Or perhaps we may find out in season seven.
Cubs Fan ★